Tolerability and immunological effect of short up-dosing immunotherapy with 2 standardized native allergen extracts derived from the pollen of Salsola kali and Cupressus arizonica

No disponible

Non-allergenic immunotherapy

No disponible

High ambient temperature reverses hypothalamic MC4 receptor overexpression in an animal model of anorexia nervosa.

The potential involvement of the melanocortin system in the beneficial effects of heat application in rats submitted to activity-based anorexia (ABA), an analogous model of anorexia nervosa (AN), was studied. Once ABA rats had lost 20% of body weight, half of the animals were exposed to a high ambient temperature (HAT) of 32 degrees C, whereas the rest were maintained at 21 degrees C. Control sedentary rats yoked to ABA animals received the same treatment. ABA rats (21 degrees C) showed increased Melanocortin 4 (MC4) receptor and Agouti gene Related Peptide (AgRP) expression, and decreased pro-opiomelanocortin (POMC) mRNA levels (Real Time PCR), with respect to controls. Heat application increased weight gain and food intake, and reduced running rate in ABA rats, when compared with ABA rats at 21 degrees C. However, no changes in body weight and food intake were observed in sedentary rats exposed to heat. Moreover, heat application reduced MC4 receptor, AgRP and POMC expression in ABA rats, but no changes were observed in control rats. These results indicate that hypothalamic MC4 receptor overexpression could occur on the basis of the characteristic hyperactivity, weight loss, and self-starvation of ABA rats, and suggest the involvement of hypothalamic melanocortin neural circuits in behavioural changes shown by AN patients. Changes in AgRP and POMC expression could represent an adaptative response to equilibrate energy balance. Moreover, the fact that HAT reversed hypothalamic MC4 receptor overexpression in ABA rats indicates the involvement of brain melanocortin system in the reported beneficial effects of heat application in AN. A combination of MC4 receptor antagonists and heat application could improve the clinical management of AN.

Effects of fluoxetine administration on hypothalamic melanocortin system in obese Zucker rats.

The aim of the present work was to study the potential involvement of melanocortin system in the anorectic mechanism of fluoxetine, a selective serotonin reuptake inhibitors, in obese Zucker rats. Male obese Zucker (fa/fa) rats were administered fluoxetine (10 mg/kg; i.p.) daily for two weeks. The control group was given 0.9% NaCl solution. RT-PCR for pro-opiomelanocortin (POMC), Agouti gene related peptide (AgRP) and melanocortin receptor 4 (MC4-R) in the hypothalamus, as well as regional immunostaining for alpha-melanocyte stimulating hormone (alpha-MSH) and MC4-R were carried out. Fluoxetine administration increased POMC expression and reduced MC4-R expression in the hypothalamus, without changes in AgRP mRNA levels. Moreover, an increase in the numbers of alpha-MSH positively immunostained neural cells in the hypothalamic arcuate nucleus (ARC), as well as a significant decrease in the numbers of neural cells positively immunostained for MC4-R in the paraventricular nucleus (PVN), without changes in lateral hypothalamic area (LHA), were observed. These results suggest the involvement of alpha-MSH in central fluoxetine anorectic action.

Sibutramine decreases body weight gain and increases energy expenditure in obese Zucker rats without changes in NPY and orexins.

The aim of the present work was to describe the effects of sibutramine on body weight and adiposity and to establish the potential involvement of neuropeptide Y (NPY) and orexins in the anorectic action of this drug. Male obese Zucker rats were daily administered with sibutramine (10 mg/kg, intraperitoneal) for two weeks. Carcass composition was assessed using the official methods of the Association of Official Analytical Chemists. Total body oxygen consumption was measured daily for 60 min before sibutramine or saline injection and for 30 min (from 60 to 90 min) after drug or saline injection. Hypothalamic arcuate and paraventricular nuclei, and the lateral hypothalamic area were immunostained for NPY, orexin A and orexin B. Commercial kits were used for serum determinations. Reductions in body weight and adipose tissue weights were observed after sibutramine treatment in obese Zucker rats. No changes in NPY immunostaining in the arcuate and paraventricular nuclei were found. Orexin A and orexin B immunostaining was not modified in the lateral hypothalamic area in treated rats. The reduction in body weight and adiposity induced by sibutramine was achieved by both a reduction in food intake and an increase in energy expenditure. NPY and orexins do not seem to be involved in the anorectic effect of sibutramine.

Brain Lys-aminopeptidase activity. Changes during cycle and pregnancy.

Lys-aminopeptidase activity levels during the estrous cycle (estrous and proestrous, in the morning and afternoon) and the pregnancy (2nd, 7th, 14th and 20th day postinsemination and the parturition day), in several areas of the rat brain, were studied in this research. The selected brain regions were the frontal, parietal and occipital cortices, olphactory bulbus, thalamus, hypothalamus, hippocampus, amygdala, striatum and pituitary gland. The most significant changes were shown in the hypothalamus and the pituitary gland. Thus, in these areas, the higher cyclic enzyme levels were found in the proestrous stage. During pregnancy, there was a rise on the 7th and 14th days, with a decrease on the 20th day. Also, similar changes in the occipital cortex, striatum, hippocampus and amygdala were appreciated, but fewer than those observed in the hypothalamus and the pituitary. In conclusion, the activity of the aminopeptidase under study fluctuates during the estrous cycle and during pregnancy, as well as in the hypothalamic-pituitary axis and also in several extrahypothalamic areas of the rat brain.

Leu-arylamidase activity levels during the estrous cycle and pregnancy in several extrahypothalamic areas of the rat brain.

A wide variety of behavioral changes in the female rat have been associated with the estrous cycle, pregnancy, and the postpartum period and their accompanying hormonal fluctuations. Since aminopeptidase activity, that presumably controls the activity of several neuroactive peptides, has been implicated in the control of these hormonal changes, the present study examined the tissue levels of Leu-arylamidase activity (Leu-ArA) in the cortices (frontal, parietal and occipital), striatum, hippocampus, amygdala, pineal gland and medulla oblongata during the estrous cycle, different stages of pregnancy (2nd, 7th, 14th and 20th postinsemination day) and the postpartum day. In the estrous cycle, Leu-ArA was significantly increased during the afternoon of the proestrous in the occipital cortex, amygdala and medulla oblongata. In general, higher enzyme levels were found during the middle stages of pregnancy. There is a significant rise after parturition in the occipital cortex, and clear but insignificant increases in the striatum and medulla. It is suggested that several extrahypothalamic areas may mediate several effects on Gn-RH secretion from the hypothalamus, and that Leu-ArA could be implicated.

Neutral aminopeptidase activity levels during the estrous cycle and the pregnancy in the hypothalamus and the pituitary of the rat.

Neutral aminopeptidase activity levels during the estrous cycle and pregnancy, in the hypothalamus and the pituitary of experimental animals, was studied in this research. The cyclic stages were the estrous, diestrous and proestrous (at morning and afternoon). The pregnancy phases were the 2nd, 7th, 14th and 20th day postinsemination. The parturition day was also studied. The higher cyclic enzyme levels were found in the proestrous stage (afternoon). No differences between estrous and diestrous were observed. During pregnancy, there was a rise at 7th and 14th day, with a decrease in the 20th day. In the hypothalamus, significant increases after parturition were shown, the latter not being observed in the pituitary. In general, the changes seem to be parallel to those of the luteinizing hormone.

[Acetylcholinesterase activity during the cortical development of the cat brain]. / Actividad de acetilcolinesterasa durante el desarrollo cortical del cerebro de gato.

Acetylcholinesterase (AChe) hydrolyses acetylcholine to choline and acetate, thereby inactivating the neurotransmitter. However, the possible non-cholinergic function of this enzyme has been recently suggested. In the present work, changes in AChe activity during the postnatal development of the cat brain are described, in order to show if the enzyme could play a part in the maturing processes of the CNS. The study was performed in the frontal and parietal cortices, area 17 and areas 18 and 19 as a whole in the 15 and 30 days postnatal stages. Significant increases with age were observed in all the brain areas under study. It is suggested that this enzyme activity play a part in the maturation of the cat brain cortices, possibly in the cholinergic development and/or as a cell growth regulatory factor.

Cyclic changes of exopeptidase activities in the rat brain: a regional study.

The present report describes the activity of three neuropeptide-degrading enzymes, in 12 brain areas during the estrous cycle of Sprague-Dawley rats. The quantitation of the enzyme activities was performed by measuring the rate of hydrolysis of the chromogenic substrates Leu-, Lys- and Asp-2-naphthylamides, by neutral, basic and acid aminopeptidase (AP) activities, respectively. Lys- and Leu-AP activities show a significant increase during the proestrus stage in the hypothalamus and the pituitary gland. Also there is a significant increase of Leu-AP activity in the occipital cortex. No significant decreases for Asp-AP activity during the proestrus in the hypothalamus and the pituitary were observed. As the changes seem to be limited at the hypothalamic-pituitary axis, these findings could be interpreted to mean that these exopeptidase activities play a role in the hormonal changes that take place during the estrous cycle of the rat.

Lys- and Tyr-arylamidase activities in serum and brain during the estrous cycle of the rat.

Peptidase enzymes are involved in neuropeptide processing or degradation. In order to analyse a possible functional participation of these enzymes, arylamidase activity of several rat brain regions and serum was assayed in the soluble fraction during the estrous cycle using L-Lys- and L-Tyr-beta-naphthylamide as substrates. Significant differences were present in the hypothalamus, the pituitary and serum when both substrates were used. However, there were no differences in cortical areas. These results suggest a role for arylamidase activity in the hormonal changes that happen during the estrous cycle of the rat.